Night guard. Wearing a night guard will protect your teeth from clenching. See your dentist about this.
Evaluations. This is a complex issue and usually does not have a simple answer. In fact, the subject requires much more room than available here. Answer dependent upon acute\chronic? Dental\medical\combination? I would recommend you start with a consult with a dentist, especially one knowledgeable about sleep and tmd disorders, and also your physician for medical factors. It requires one on one consults.